A data network is generally consisted of a network of nodes connected by point-to-point links. Each physical link may support a number of logical point-to-point channels. Each channel may be a bi-directional communication path for allowing commands and data to flow between two connect nodes (e.g., hosts, I/O units and switch/switch elements) within the network. Each channel may refer to a single point-to-point connection where data may be transferred between endpoints (e.g., hosts and I/O units) in strict first-in, first-out (FIFO) order. Data may be transmitted in packets including groups called cells from source to destination often through intermediate nodes. In many data networks, cells between two endpoints (e.g., hosts and I/O units) may transverse the network along a given channel to ensure that cells are delivered in the order in which they were transmitted. However, strict FIFO ordering of messages in such a data network causes a well known problem called “head-of-line blocking.” Usually the “head-of-line blocking” problem arises when a high priority message is queued onto the tail of a FIFO queue, and has to wait for all other messages to be processed before the high priority message may reach the head of the FIFO queue for processing. As a result, the overall performance of the data network can be significantly degraded.
Therefore, there is a need for a more flexible, cost-effective, priority-driven and performance-efficient technique for providing prioritized data movement between endpoints connected by multiple logical channels in a data network.